// Emacs style mode select   -*- C++ -*-
//-----------------------------------------------------------------------------
//
// Copyright (C) 1993-1996 by id Software, Inc.
//
// This program is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation; either version 2
// of the License, or (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// DESCRIPTION:
//      Plats (i.e. elevator platforms) code, raising/lowering.
//
//-----------------------------------------------------------------------------

#include "i_system.h"
#include "z_zone.h"
#include "m_random.h"

#include "doomdef.h"
#include "p_local.h"

#include "s_sound.h"

// State.
#include "doomstat.h"
#include "r_state.h"

// Data.
#include "sounds.h"

plat_t*         activeplats[MAXPLATS];

//
// Move a plat up and down
//
void T_PlatRaise(plat_t* plat)
{
    result_e    res;

    switch(plat->status)
    {
      case up:
        res = T_MovePlane(plat->sector,
                          plat->speed,
                          plat->high,
                          plat->crush,0,1);

        if (plat->type == raiseAndChange
            || plat->type == raiseToNearestAndChange)
        {
            if (!(leveltime&7))
                S_StartSound((mobj_t *)&plat->sector->soundorg,
                             sfx_stnmov);
        }

        if (res == crushed && (!plat->crush))
        {
            plat->count = plat->wait;
            plat->status = down;
            S_StartSound((mobj_t *)&plat->sector->soundorg,
                         sfx_pstart);
        }
        else
        {
            if (res == pastdest)
            {
                plat->count = plat->wait;
                plat->status = waiting;
                S_StartSound((mobj_t *)&plat->sector->soundorg,
                             sfx_pstop);

                switch(plat->type)
                {
                  case blazeDWUS:
                  case downWaitUpStay:
                    P_RemoveActivePlat(plat);
                    break;

                  case raiseAndChange:
                  case raiseToNearestAndChange:
                    P_RemoveActivePlat(plat);
                    break;

                  default:
                    break;
                }
            }
        }
        break;

      case      down:
        res = T_MovePlane(plat->sector,plat->speed,plat->low,false,0,-1);

        if (res == pastdest)
        {
            plat->count = plat->wait;
            plat->status = waiting;
            S_StartSound((mobj_t *)&plat->sector->soundorg,sfx_pstop);
        }
        break;

      case      waiting:
        if (!--plat->count)
        {
            if (plat->sector->floorheight == plat->low)
                plat->status = up;
            else
                plat->status = down;
            S_StartSound((mobj_t *)&plat->sector->soundorg,sfx_pstart);
        }
      case      in_stasis:
        break;
    }
}

//
// Do Platforms
//  "amount" is only used for SOME platforms.
//
int
EV_DoPlat
( line_t*       line,
  plattype_e    type,
  int           amount )
{
    plat_t*     plat;
    int         secnum;
    int         rtn;
    sector_t*   sec;

    secnum = -1;
    rtn = 0;

    //  Activate all <type> plats that are in_stasis
    switch(type)
    {
      case perpetualRaise:
        P_ActivateInStasis(line->tag);
        break;

      default:
        break;
    }

    while ((secnum = P_FindSectorFromLineTag(line,secnum)) >= 0)
    {
        sec = &sectors[secnum];

        if (sec->specialdata)
            continue;

        // Find lowest & highest floors around sector
        rtn = 1;
        plat = Z_Malloc( sizeof(*plat), PU_LEVSPEC, 0);
        P_AddThinker(&plat->thinker);

        plat->type = type;
        plat->sector = sec;
        plat->sector->specialdata = plat;
        plat->thinker.function.acp1 = (actionf_p1) T_PlatRaise;
        plat->crush = false;
        plat->tag = line->tag;

        switch(type)
        {
          case raiseToNearestAndChange:
            plat->speed = PLATSPEED/2;
            sec->floorpic = sides[line->sidenum[0]].sector->floorpic;
            plat->high = P_FindNextHighestFloor(sec,sec->floorheight);
            plat->wait = 0;
            plat->status = up;
            // NO MORE DAMAGE, IF APPLICABLE
            sec->special = 0;

            S_StartSound((mobj_t *)&sec->soundorg,sfx_stnmov);
            break;

          case raiseAndChange:
            plat->speed = PLATSPEED/2;
            sec->floorpic = sides[line->sidenum[0]].sector->floorpic;
            plat->high = sec->floorheight + amount*FRACUNIT;
            plat->wait = 0;
            plat->status = up;

            S_StartSound((mobj_t *)&sec->soundorg,sfx_stnmov);
            break;

          case downWaitUpStay:
            plat->speed = PLATSPEED * 4;
            plat->low = P_FindLowestFloorSurrounding(sec);

            if (plat->low > sec->floorheight)
                plat->low = sec->floorheight;

            plat->high = sec->floorheight;
            plat->wait = 35*PLATWAIT;
            plat->status = down;
            S_StartSound((mobj_t *)&sec->soundorg,sfx_pstart);
            break;

          case blazeDWUS:
            plat->speed = PLATSPEED * 8;
            plat->low = P_FindLowestFloorSurrounding(sec);

            if (plat->low > sec->floorheight)
                plat->low = sec->floorheight;

            plat->high = sec->floorheight;
            plat->wait = 35*PLATWAIT;
            plat->status = down;
            S_StartSound((mobj_t *)&sec->soundorg,sfx_pstart);
            break;

          case perpetualRaise:
            plat->speed = PLATSPEED;
            plat->low = P_FindLowestFloorSurrounding(sec);

            if (plat->low > sec->floorheight)
                plat->low = sec->floorheight;

            plat->high = P_FindHighestFloorSurrounding(sec);

            if (plat->high < sec->floorheight)
                plat->high = sec->floorheight;

            plat->wait = 35*PLATWAIT;
            plat->status = P_Random()&1;

            S_StartSound((mobj_t *)&sec->soundorg,sfx_pstart);
            break;
        }
        P_AddActivePlat(plat);
    }
    return rtn;
}

void P_ActivateInStasis(int tag)
{
    int         i;

    for (i = 0;i < MAXPLATS;i++)
        if (activeplats[i]
            && (activeplats[i])->tag == tag
            && (activeplats[i])->status == in_stasis)
        {
            (activeplats[i])->status = (activeplats[i])->oldstatus;
            (activeplats[i])->thinker.function.acp1
              = (actionf_p1) T_PlatRaise;
        }
}

void EV_StopPlat(line_t* line)
{
    int         j;

    for (j = 0;j < MAXPLATS;j++)
        if (activeplats[j]
            && ((activeplats[j])->status != in_stasis)
            && ((activeplats[j])->tag == line->tag))
        {
            (activeplats[j])->oldstatus = (activeplats[j])->status;
            (activeplats[j])->status = in_stasis;
            (activeplats[j])->thinker.function.acv = (actionf_v)NULL;
        }
}

void P_AddActivePlat(plat_t* plat)
{
    int         i;

    for (i = 0;i < MAXPLATS;i++)
        if (activeplats[i] == NULL)
        {
            activeplats[i] = plat;
            return;
        }
    I_Error ("P_AddActivePlat: no more plats!");
}

void P_RemoveActivePlat(plat_t* plat)
{
    int         i;
    for (i = 0;i < MAXPLATS;i++)
        if (plat == activeplats[i])
        {
            (activeplats[i])->sector->specialdata = NULL;
            P_RemoveThinker(&(activeplats[i])->thinker);
            activeplats[i] = NULL;

            return;
        }
    I_Error ("P_RemoveActivePlat: can't find plat!");
}
